Light Pollution Is Increasing Air Pollution Levels

Next time you look up at the night sky, but can’t see the stars due to light pollution, you should be more worried that the world’s air pollution is getting worse. That’s right, according to a National Oceanic and Atmospheric Administration researcher, a chemical called nitrate radical, which breaks down harmful emissions emitted by cars and factories, is being hampered by street lights.

Harald Stark, from the US National Oceanic and Atmospheric Administration, conducted tests over Los Angeles that showed that lights from buildings, street lights and cars suppressed the nitrate radical.

“Our first results indicate that city lights can slow down the night-time cleansing by up to 7% and they can also increase the starting chemicals for ozone pollution the next day by up to 5%,” Stark told the BBC. “More work needs to be done to really quantify the next step which would be how much ozone could we actually have the next day. This work would be important to undertake because many cities are close to their regulatory limits in terms of ozone levels, so even a small effect such as this could be important.”

Despite our artificial lights being much dimmer than the sun, it is amazing to learn that they can have such an adverse effect. Stark does however pose a possible solution focused on switching the lights to another color such as red. While this may be impractical, Stark has another, more simple remedy: focusing lights downwards. Less overhead light would minimize the effects on the nitrate radical in the atmosphere.